Synergistically Enhanced Peroxidase-like Activity of FeSe 2 /rGO Nanohybrids: Kinetic, Mechanistic, and Molecular Docking Studies

FeSe 2 /rGO nanohybrids were prepared via in situ one-pot synthesis using the hydrothermal method and were assessed for their potential for peroxidase-like activity. Structural and morphological analysis using FE-SEM and TEM confirmed the successful in situ growth and uniform distribution of FeSe 2 NPs onto the rGO nanosheet matrix. Furthermore, the FeSe 2 /rGO nanohybrids showed superior and enhanced peroxidase-like activities compared to the bare FeSe 2, as demonstrated using two substrates, 3,3′,5,5′-tetramethylbenzidine (TMB) and o-phenylenediamine (OPD). Michaelis–Menten kinetics showed a significantly lower K m of 0.00952 mM for TMB and 7.62 mM for H 2 O 2, along with a high V max of 6.48 × 10 −8 M s −1 (TMB) and 1.706 × 10 −6 Ms −1 (H 2 O 2 ) for FeSe 2 /rGO, outperforming bare FeSe 2 and several other reported nanozymes. The kinetic parameters showed a strong substrate affinity and improved catalytic efficiency. Mechanistic study using terephthalic acid (fluorescent probe) revealed that • OH is majorly responsible for substrate oxidation, which is significantly enhanced by the synergistic effect of FeSe 2 and rGO. Furthermore, in support of our experimental results, molecular docking studies with multiple peroxidase proteins also showed significantly higher binding affinities for FeSe 2 /rGO (–9.9 to –11.9 kcal mol −1 ), as compared to FeSe 2 (–4.8 to –9.1 kcal mol −1 ). Overall, this work highlights FeSe 2 /rGO as a robust peroxidase mimic and efficient nanozyme with strong potential for colorimetric sensing and catalytic performance.